1,3-Dienones and 2<i>H</i>-Pyran-2-ones from Soft α-Vinyl Enolization of β-Chlorovinyl Ketones: Defined Roles of Brönsted and Lewis Base
作者:Hun Young Kim、Kyungsoo Oh
DOI:10.1021/acs.orglett.5b03265
日期:2015.12.18
The eliminative reaction pathways of (E)-β-chlorovinyl ketones were investigated in the presence of both Brönsted and Lewis bases. The Brönsted base, Et3N, effected the soft α-vinyl enolization of (E)-β-chlorovinyl ketones to [3]cumulenol intermediates; in turn, a catalytic amount of Lewis base, PPh3, initiated isomerization to provide 1,3-dienones in high yields. The introduction of a carbon-based
在布朗斯台德碱和路易斯碱的存在下研究了(E)-β-氯乙烯基酮的消除反应途径。布朗斯台德碱Et 3 N影响了(E)-β-氯乙烯基酮向[3]异丙苯三酚中间体的软α-乙烯基烯醇化作用。进而,催化量的路易斯碱PPh 3引发了异构化反应,以高收率提供了1,3-二烯酮。将碳基亲核试剂引入反应混合物中,可在一锅中高效合成2 H -pyran-2-one,其中碳基亲核试剂是由额外等价的布朗斯台德碱Et 3生成的N,攻击亲电的[3]枯烯酚中间体以起始环化,得到2 H-吡喃-2-酮。
A facile synthesis of 3,4-dimercaptofurans via sulfenylation of (E)-β-chlorovinyl ketones and 1,2-sulfur migration
作者:E. Song、H. Y. Kim、K. Oh
DOI:10.1039/c6ob02772e
日期:——
The one-pot sulfenylation of (E)-β-chlorovinyl ketones was investigated under soft α-vinyl enolization conditions. Modulating the nature of nucleophilic species using a “hard” base the regioselective formation of α,γ-dithio-allenyl ketones has been achieved, where the thermodynamic control was mimicked by the presence of Et3N·HCl. The sulfenylated products, α,γ-dithio-allenyl and α,α-dithio-propargyl
Ambivalent Reactivity Modes of β-Chlorovinyl Ketones: Electrophilic Lithium [3]Cumulenolates from Soft Vinyl Enolization Strategy
作者:Hun Young Kim、Edward Oscar Rooney、Raymond Phillip Meury、Kyungsoo Oh
DOI:10.1002/anie.201302750
日期:2013.7.29
Soft spot: The softvinylenolization of (E)‐β‐chlorovinyl ketones results in the in situ generation of electrophiliclithium [3]cumulenolates, which react with nucleophiles such as another lithium [3]cumulenolate to stereoselectively form vinyl allenones. They can also react with ketimine esters to give 3‐methylenepyrrolidines.
A Soft Vinyl Enolization Approach to α-Acylvinyl Anions: Direct Aldol/Aldol Condensation Reactions of (<i>E</i>)-β-Chlorovinyl Ketones
作者:Hun Young Kim、Jian-Yuan Li、Kyungsoo Oh
DOI:10.1002/anie.201209876
日期:2013.3.25
Synthesizing the synthons: The development of α‐acylvinyl anion synthons has been achieved using direct α‐vinyl enolization of α,β‐unsaturated ketones under mild reaction conditions. The synthetic utility of such synthons has been demonstrated in intermolecular aldol and aldol condensation reactions, which provide synthetically useful allenyl ketone and enyne derivatives.
Continuous Flow Synthesis of 1,4-Benzothiazines Using Ambivalent Reactivity of (<i>E</i>)-β-Chlorovinyl Ketones: A Point of Reaction Control Enabled by Flow Chemistry
作者:Satheesh Borra、Soyeon Chae、Hun Young Kim、Kyungsoo Oh
DOI:10.1021/acs.orglett.2c01865
日期:2022.7.29
A continuous flow system to 1,4-benzothiazines was developed using the point of reaction control, where the ambivalent (E)-β-chlorovinyl ketones and 2,2′-dithiodianilines were confined in a diffusion controlled flow setting. The successful segregation of reactive chemical species in a flow setting allowed more defined reaction pathways that are not feasible in traditional batch reaction conditions
使用反应控制点开发了 1,4-苯并噻嗪的连续流动系统,其中二价 ( E )-β-氯乙烯基酮和 2,2'-二硫代二苯胺被限制在扩散控制的流动设置中。在流动环境中成功分离反应性化学物质允许更明确的反应路径,这在传统的间歇反应条件下是不可行的。流动系统中的反应控制点有助于执行经常受到同时产生多种化学物质的困扰的反应。